1. Field of the Invention
The invention relates in general to video decoding, and in particular, to a video decoding method capable of detecting and correcting missing or undecodable video frames.
2. Description of the Related Art
Various functionalities are implemented in video apparatuses in order to conveniently manipulate video data. Video CODECs (encoders/decoders) typically comply with video coding standards such as MPEG 1/2/4 and H.26x to perform digital data manipulation and compression. These compression techniques achieve relatively high compression ratios by discrete cosine transform (DCT) techniques and motion compensation (MC) techniques, so that the compressed video streams can be transmitted across various digital networks or stored in various storage medium in an efficient manner.
However, since MPEG 1/2/4 and H.26x video encoding employs compression schemes which encode later video frames based on earlier video frames, when unrecoverable errors are introduced into a video bitstream during transmission, these errors found in earlier video frames can render all the later dependent frames undecodable. Typically, the video encoder skips the undecodable video frame and repeats an early decodable frame, resulting in abrupt scene changes or discontinuous movement due to a number of video frames being skipped, thus resulting in unpleasant viewing experiences for users. Therefore, there exists a need for video decoding methods capable of detecting unrecoverable errors in video bitstreams and reducing motion jerkiness to alleviate degradation of video quality due to these unrecoverable errors.